I'm attempting to plug in a second monitor today into the DVI port and I'm not getting any signal and the screen resolution settings does not detect the monitor automatically like my notebook(also running mint 6) does

Which editions do you run? (main, KDE, other)Do you still get image from the VGA connector?The DVI-i has analog in it - are you sure you are trying to use the digital signal (that should be the case)Have you tried to use nvidia-settings (as root)